Hydrothermal synthesis of WSe2 films and their application in high-performance photodetectors

In this paper, a hydrothermal strategy is developed to synthesize high-quality WSe2 films on a quartz substrate. N, N-dimethylformamide (DMF) and deionized water are used as double solvent, and low-cost selenium powder and sodium tungstate dehydrate are used as the Se and W sources, respectively. Characterizations with X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy and transmission electron microscopy confirm the high quality of hexagonal WSe2 films. Photodetectors, which are assembled based on such solution-processed WSe2 films, exhibit a high photoresponsivity and a short response time. This study suggests that WSe2 films are very promising for optoelectronic applications which require low cost, large area and process simplicity.